Voyager 1 is a space probe launched by NASA on September 5, 1977. Part of the Voyager program to study the outer Solar System, Voyager 1 launched 16 days after its twin, Voyager 2. Having operated for 40 years and 10 days as of September 15, 2017, the spacecraft still communicates with the Deep Space Network to receive routine commands and return data. At a distance of 139 AU (2.08×1010 km) from the Sun as of July 1, 2017, it is the farthest spacecraft from Earth as well as the farthest man-made object. It is also the most distant object in the solar system whose location is known, even farther than Eris (96 AU) and V774104 (~103 AU).